An automatic analyzer quantitatively or qualitatively analyzing specific components included in blood, urine or the like is necessary for a present diagnosis in view of the repeatability of an analysis result, high process speed or the like.
The measuring methods of an automatic analyzer are classified roughly into an analysis method (the colorimetric analysis) using a reagent reacting the analysis object component of a sample to change the color of the reaction solution, and an analysis method (the immunity analysis) using a reagent adding markers into materials specifically binding object components directly or indirectly to count the markers.
In every analysis methods, the predetermined amount of regent is mixed into a sample to execute an analysis. Recently, an analysis apparatus is required to reduce the amount of reagents used for an analysis in response to the request for reducing the cost of the analysis. The amount of a sample used for one analysis in the present automatic analyzer is a digit micro litter order, and the maintenance of the high dispensing accuracy is required at the same time.
According to the method described in the Patent Document 1 for maintaining the high reliability in the low dispensing amount about 1 micro litter, after a sample is discharged in a sample container, a nozzle is moved at a low speed until the nozzle is separated from the sample, so that the amount of the sample attached to the nozzle is reduced to improve the dispensing accuracy of the sample.
Further, according to a method described in the Patent Document 2, when a sample is discharged into a reaction container, the gap between the bottom of the reaction container and the tip of a sample probe is kept at a constant value, and the sample probe is moved upwardly while the sample probe dispenses the sample, so that the sample is prevented from attaching to the side surface of the sample probe to improve the dispensing accuracy.